Cairns Water Security

The tender design process required integration of multiple external design partners across civil, structural, mechanical, electrical, and process disciplines into a single, constructible solution aligned to bid strategy and budget. Phronis performed the design management role to achieve a seamless design team.

Complex infrastructure conditions added further challenge. The new $350M water treatment plant was located on a sloping hillside, requiring careful coordination between process layout, bulk earthworks and structural stability. Potable water reservoirs were positioned on a hilltop, necessitating safe heavy vehicle access, compliant turning geometry and environmentally sensitive road design.

Approximately 30km of brownfield pipeline needed to integrate into Cairns’ existing hydraulic network without compromising operability. All elements had to demonstrate constructability, cost certainty and long-term performance within a competitive ECI tender framework.

We implemented structured design coordination and disciplined tender management practices to align technical development with commercial objectives.

Regular multi-consultant workshops and formal review cycles ensured clear accountability and integrated design progression. Constructability and risk reviews were embedded early, engaging construction and safety specialists to validate assumptions and reduce downstream exposure.

Iterative option development was undertaken for treatment plant configuration and access road alignments, balancing safety, environmental constraints, earthworks volumes and cost impacts. Budget and schedule oversight were maintained throughout to protect bid competitiveness.

Stakeholder engagement ensured Seymour Whyte and client representatives were kept informed of risks, trade-offs and design maturity at each stage.

The coordinated tender design provided Seymour Whyte with a robust, integrated and commercially defensible submission. The tender design was delivered on time to allow for the FCI tender to be submitted.

The bid demonstrated constructability across complex hillside and hilltop sites, validated hydraulic integration and realistic cost and schedule assumptions. Risk identification and mitigation were clearly articulated, strengthening confidence in delivery capability.

By aligning technical disciplines, constructability considerations and tender strategy, we contributed to a successful ECI outcome and positioned the Cairns Water Security Stage 1 project for secure long-term water infrastructure delivery.